Improvement in dial-telegraph instruments



S. CHEST-ER.

Improvement in Dial Telegraph-InstrumentS. N0. 1218 ](]8 Patented July 9,1872.

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issues STEPHEN cHEsrEE,'oE-EL1zABETH, 'nEw JEEsEY.

IMPROVEMENT IN DIAL-TELEGRAPH INSTRUMENTS.

Specification formingapartot' LetterePatent No.128t708, dated'JulyS; "i872."

. fall whom it may concern:

Be it known that I, STEPHEN CHESTEIg of the city of Elizabeth, county of Union and State of New Jersey, have invented a new and useful Improvement in Telegraph Instruments; and the following is a true and accurate description thereof, reference being had to the accompanying drawing and the letters and figures thereon designating the several parts. e

My invention consists in a device for-renderin g the electric impulses sent from a manual transmitter to control the moi ements of a dial instrumentor the type-wheel of a printing instrument uniform in-the length of opening and closing and in the velocity with which they succeed each other.

Referring to the drawing, Figure I is a view of the external dial-plate A and handle or manipulator a 1), part of -the dial-plate being stripped off to expose in the interior the parts otherwise concealed. Fig. 2 is aside view of the same parts, and Eig. 3 is a view of part of Fig. 1 reversed.

The parts ordinarily belonging to a manipulator or transmitter are the handle and bar a and b, the ratchet-wheel B and pawl E, and circuit-wheel D, all rigidly fastened upon a common shaft, P, ,with the springs K, or their equivalent, impinging upon the circumference of the circuit-wheel. This latter has teeth the handle a b be moved forward (to the right) The teeth of the circuit-wheel passing over the springs K will cause the circuit to be opened and closed a number of times corresponding to the number of divisions of the dial-plate passed over by the handle. The connection of the circuit-wheel and springs with line-batteries and receiving instruments requires no description, being of'common use. The object of ratchet-wheel B and pawl E is to prevent an accidental reverse movement of the handle and circuit-wheel, which would cause a greater number of electric impulses to be sent than that indicated by the position of the'handle upon the dial-plate. The fault in this simple method of transmission of electric signals is that it is extremely difiicult for any person without long practice and care to avoid commencing the movement of the arm with a rapid jerk and terminating it at the desired letter or sign with greatly diminished velocity and hesitation; hence the first few impulses sent are frequently so rapid and flighty that the magnet of the receiving instrument'fails to fully respond and the needle or type-wheel, as the case may he, fails to move in accord with the transmitting-handle; therefore this manipulator can only be used rapidly by carefully-trained experts.

My'improvem'ent consists, first, in attaching to the circuit-wheel D the escapementwheel C. The latter wheel has a number of teeth corresponding to the number of teeth and spaces on circuit-wheel D. Secondly, in placing these loosely upon the shaft 19 and attachin g them thereto by means of a flat spiral spring or" its equivalent, one end of which-is made fast to the shaft]? and the other to the combined wheels D and O. A pin is so placed upon the shaft P as to prevent the movement of the combined. wheels in thefdirection in which the spring 8 pulls beyond a certain point. Therefore, if the handle and shaft be quickly moved forward, the combined wheels will move forward only because of the increased tension of the spring and because thepin or stop has been moved forward. The velocity and regularity of this motion are con trolled by the pallet I, which plays in-the teeth of the escapement-wheel O. 'A flapper or pendulum may be attached to the pallet. As the combined wheels must, therefore, follow the usual movement of escapements, the

circuit-wheel will therefore move in regular pulsations, however rapidly it may be .permitted to move, the springs resting alternately in the center of a tooth and center of a space. Hence, if the handle be moved from one point to another withany degree of rapidity and'flightiness, the circuit-wheel will either of them, for ,the purposes described,

' such combinations being in common use; but

I claim- 1. The combination of a wheel and revolving shaft passing through the center thereof, but attached to each other only by an elastic spiral spring, or its equivalent, to open, close, or change currents of electricity, substantially in the manner and for the purposes hereinbefore set forth.

2. The combination of circuit and escapement wheels, controlled by a pallet, with a shaftpassingthrough the center of said yvheels, but revolving independently thereof, and an elastic spring or its equivalent connecting them, to open, close, or change electric currents in transmitting or receiving electro-telegraph instruments, substantially in the. manner as hereinbefore set forth.

STEPHEN CHESTER.

Witnesses:

VAN ZANDT DAWES, CHARLES T. POLHAMUS. 

